1. An electronic product metal shell comprising:a metal layer having a first surface and a second surface;
a hard anodic oxidation layer coated on the first surface and the second surface of the metal layer;
a step recess formed through the hard anodic oxidation layer on the first surface of the metal layer and partially into the metal layer;
an antenna groove disposed within the step recess and extending through the metal layer to expose an inner side of the hard anodic oxidation layer on the second surface of the metal layer; and
a non-conductive material filled in the antenna groove.